CN112578227A - Load detection device and method, and unmanned device charging system - Google Patents
Load detection device and method, and unmanned device charging system Download PDFInfo
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- CN112578227A CN112578227A CN202011474753.8A CN202011474753A CN112578227A CN 112578227 A CN112578227 A CN 112578227A CN 202011474753 A CN202011474753 A CN 202011474753A CN 112578227 A CN112578227 A CN 112578227A
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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Abstract
The embodiment of the invention discloses a load detection device and method and an unmanned device charging system. The device includes: a power supply loop for supplying power to a load; a voltage acquisition circuit configured to acquire a voltage signal from the power supply loop; the first controllable switch is arranged between the voltage acquisition circuit and the power supply loop; and a processor configured to: controlling the first controllable switch to be closed; acquiring a voltage signal acquired by a voltage acquisition circuit; the state of the supply circuit is determined from the fluctuations of the voltage signal. Therefore, the load detection device provided by the embodiment of the invention can not only detect whether a short circuit phenomenon exists, but also judge whether the load is connected, so that the risk of element damage caused by large current under the condition that the load is short-circuited is reduced.
Description
Technical Field
The invention relates to the technical field of load detection, in particular to a load detection device and method and an unmanned device charging system.
Background
The load detection circuit is a circuit for detecting whether the power supply equipment connecting section is connected with a load. The load refers to an electric device connected to both ends of a power supply in a circuit, and is classified into an inductive load, a resistive load, a capacitive load, and the like. At present, for a load detection circuit connected to a power supply device, after an external connector is connected to a load, the load may be equivalent to a resistor, and as long as it is ensured that a resistance value of a voltage dividing resistor is much larger than a resistance value of a load equivalent resistor, a voltage value or a range detected by a Central Processing Unit (CPU) may be determined by allocating the voltage dividing resistor. When the LOAD is not connected, the LOAD pin of the CPU has no voltage or is very low, and the external LOAD can be judged not to be connected at the moment, and the starting is not allowed in the program. However, when there is a short circuit condition in the external load and a physical short circuit is caused by reverse insertion of the load interface and the power interface, a false start operation may also be caused, and at this time, the power supply device has a risk of burning the circuit board due to a large current, which may cause a fire more seriously.
Disclosure of Invention
The embodiment of the invention aims to provide a load detection device and method and an unmanned device charging system, which are used for solving the problem that an existing load detection circuit is easy to cause element damage under the condition that a load is short-circuited.
In order to achieve the above object, a first aspect of an embodiment of the present invention provides a load detection apparatus, including:
a power supply loop for supplying power to a load;
a voltage acquisition circuit configured to acquire a voltage signal from the power supply loop;
the first controllable switch is arranged between the voltage acquisition circuit and the power supply loop; and
a processor configured to:
controlling the first controllable switch to be closed;
acquiring a voltage signal acquired by a voltage acquisition circuit;
the state of the supply circuit is determined from the fluctuations of the voltage signal.
In an embodiment of the invention, the processor being configured to determine the state of the supply loop from fluctuations in the voltage signal comprises: the processor is configured to:
determining the fluctuation rule of the voltage signal;
comparing the fluctuation rule with a preset fluctuation rule;
determining that the power supply loop is short-circuited under the condition that the fluctuation rule does not match the preset fluctuation rule; and under the condition that the fluctuation rule is matched with the preset fluctuation rule, determining that the power supply loop is not short-circuited.
In an embodiment of the invention, the power supply circuit comprises a second controllable switch for controlling the switching of the power supply circuit, the processor is further configured to:
and controlling the second controllable switch to be closed under the condition that the power supply loop is determined not to be short-circuited.
In an embodiment of the invention, the processor configured to acquire the voltage signal acquired by the voltage acquisition circuit comprises:
the processor is configured to acquire a voltage signal acquired by the voltage acquisition circuit within a preset time.
In an embodiment of the present invention, the preset fluctuation law is determined by the following formula:
U＝E(1-e-t/RC)；
wherein, U is a real-time voltage value of a load capacitor of the load, E is a steady-state voltage value of the load capacitor, C is a capacitance value of the load capacitor, and t is a preset time.
In an embodiment of the present invention, the voltage acquisition circuit includes a first resistor, a second resistor, and a third resistor; one end of the first resistor is electrically connected with one end of the second resistor, and the other end of the first resistor is electrically connected with the power supply loop through the first controllable switch; the other end of the second resistor is grounded, and a node between the first resistor and the second resistor is electrically connected with the processor through a third resistor.
In an embodiment of the present invention, the voltage acquisition circuit further includes a resistance component, the resistance component is connected in parallel with the first resistor and the second resistor connected in series; the resistance component comprises a fourth resistance and a fifth resistance which are connected in series.
In an embodiment of the invention, the processor is further configured to:
the charging time of the load is controlled by adjusting the resistance value of the resistance component.
In an embodiment of the present invention, the power supply circuit further comprises a power source, a power source connector and a load connector; the positive pole of the power supply is electrically connected with the positive pole of the power supply connector, the negative pole of the power supply is electrically connected with the negative pole of the power supply connector, the positive pole of the power supply connector is electrically connected with the positive pole of the load connector, the negative pole of the power supply connector is electrically connected with the negative pole of the load connector, and the second controllable switch is arranged between the negative pole of the power supply and the negative pole of the power supply connector.
A second aspect of embodiments of the present invention provides an unmanned aerial vehicle charging system including an unmanned aerial vehicle, a power supply apparatus, and the load detection device described above.
A third aspect of an embodiment of the present invention provides a load detection method, including:
controlling the first controllable switch to be closed so as to conduct the power supply loop and the voltage acquisition circuit;
acquiring a voltage signal acquired by a voltage acquisition circuit within a preset time;
the state of the supply circuit is determined from the fluctuations of the voltage signal.
In an embodiment of the present invention, determining the state of the power supply loop according to the fluctuation of the voltage signal includes:
determining a fluctuation rule of the voltage signal, and comparing the fluctuation rule with a preset fluctuation rule;
determining that the power supply loop is short-circuited under the condition that the fluctuation rule does not match the preset fluctuation rule;
and under the condition that the fluctuation rule is matched with the preset fluctuation rule, determining that the power supply loop is not short-circuited.
In an embodiment of the present invention, further comprising:
and under the condition that the power supply loop is determined not to be short-circuited, controlling a second controllable switch arranged on the power supply loop to be closed.
Through the technical scheme, the first controllable switch is arranged between the power supply loop and the voltage acquisition circuit, so that the processor controls the first controllable switch to be closed, the voltage signal acquired by the voltage acquisition circuit is acquired, and the state of the power supply loop is determined according to the fluctuation of the voltage signal. Therefore, the load detection device provided by the embodiment of the invention can not only detect whether a short circuit phenomenon exists, but also judge whether the load is connected, so that the risk of element damage caused by large current under the condition that the load is short-circuited is reduced.
Additional features and advantages of embodiments of the invention will be set forth in the detailed description which follows.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the embodiments of the invention without limiting the embodiments of the invention. In the drawings:
fig. 1 is a schematic structural diagram of a load detection apparatus according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a load detection device according to another embodiment of the present invention;
fig. 3 is a schematic diagram of a circuit structure of a load detection apparatus according to an embodiment of the present invention;
fig. 4 is a schematic flowchart of a load detection method according to an embodiment of the present invention.
Description of the reference numerals
1 supply loop 11 second controllable switch
12 power supply 13 power supply connector
14 load connector 15 load
2 first resistance of voltage acquisition circuit 21
22 second resistor 23 third resistor
24 fourth resistor 25 fifth resistor
3 first controllable switch 4 processor
Detailed Description
The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating embodiments of the invention, are given by way of illustration and explanation only, not limitation.
It should be noted that, if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indications are changed accordingly.
In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a load detection device according to an embodiment of the present invention. As shown in fig. 1, an embodiment of the present invention provides a load detection apparatus, which may include:
a power supply loop 1 for supplying power to a load;
a voltage acquisition circuit 2 configured to acquire a voltage signal from the power supply circuit 1;
the first controllable switch 3 is arranged between the voltage acquisition circuit 2 and the power supply loop 1; and
a processor 4 configured to:
controlling the first controllable switch 3 to close;
acquiring a voltage signal acquired by the voltage acquisition circuit 2;
the state of the supply circuit 1 is determined from the fluctuations of the voltage signal.
In an embodiment of the invention, the supply circuit 1 is a circuit for supplying a load. The load in an embodiment of the invention is a capacitive load. The capacitive load is a load with a capacitor at the input end and the output end of the power supply, the capacitive load can be equivalent to a resistor and a capacitor which are connected in parallel, and the equivalent resistor and the capacitor can be called as a load resistor and a load capacitor. The power supply circuit 1 may comprise a circuit formed by connecting a power supply, a second controllable switch and a load connector for connecting a load in series, and when the load connector is connected to the load and the second controllable switch is closed, the power supply circuit 1 forms a path, a load capacitor equivalent to the load is connected to a dc voltage source, and the load capacitor is charged.
In the embodiment of the present invention, the voltage acquisition circuit 2 is electrically connected to the power supply circuit 1, and can acquire a voltage signal from the power supply circuit 1. The collected voltage signal may include a voltage value, voltage fluctuations, and the like. A first controllable switch 3 is arranged between the voltage acquisition circuit 2 and the supply circuit 1. Under the condition that the first controllable switch 3 is closed, the power supply loop 1 and the voltage acquisition circuit 2 form a passage, and the voltage acquisition circuit 2 can acquire a voltage signal of the power supply loop 1; under the condition that the first controllable switch 3 is turned off, the power supply loop 1 and the voltage acquisition circuit 2 are not conducted, and at the moment, the voltage acquisition circuit 2 cannot acquire the voltage signal of the power supply loop 1. In one example, the first controllable switch may include, but is not limited to, a triode, a MOS Transistor, an Insulated Gate Bipolar Transistor (IGBT), and the like.
In the embodiment of the present invention, the processor 4 may control the closing of the first controllable switch 3, so that the power supply loop 1 and the voltage acquisition circuit 2 are turned on, and thereby the voltage signal acquired by the voltage acquisition circuit 2 is acquired, so as to determine the state of the power supply loop 1 according to the fluctuation of the voltage signal. A dynamic process exists in the load capacitance equivalent to the load, and the voltage of the power supply loop 1 has a certain fluctuation rule in a period of time when the first controllable switch 3 is closed. Under the condition of no load or short circuit, even if the first controllable switch 3 is closed, the voltage cannot generate a fluctuation rule, and under the condition of no short circuit, the first controllable switch 3 is closed, the voltage can generate a certain fluctuation rule. In one example, the first controllable switch 3 is closed, that is, the voltage signal fluctuates within a certain time when the power supply loop 1 and the voltage acquisition circuit 2 form a path, the processor 4 compares the fluctuation rule with a preset fluctuation rule, and determines that the power supply loop 1 is short-circuited when the fluctuation rule does not match the preset fluctuation rule; and under the condition that the fluctuation rule is matched with the preset fluctuation rule, determining that the power supply loop 1 is not short-circuited. In another example, the first controllable switch 3 is closed, i.e. the voltage signal does not fluctuate during a certain time when the power supply loop 1 and the voltage acquisition circuit 2 form a path, and at this time, the processor 4 may determine that the power supply loop 1 is short-circuited. In case of a short circuit of the power supply circuit 1, the processor 4 may control the second controllable switch of the power supply circuit 1 to be turned off, and not to charge the load, so as to protect the components in the circuit.
According to the embodiment of the invention, the first controllable switch 3 is arranged between the power supply loop 1 and the voltage acquisition circuit 2, so that the processor 4 controls the first controllable switch 3 to be closed, the voltage signal acquired by the voltage acquisition circuit 2 is acquired, and the state of the power supply loop 1 is determined according to the fluctuation of the voltage signal. Therefore, the load detection device provided by the embodiment of the invention can not only detect whether a short circuit phenomenon exists, but also judge whether the load is connected, so that the risk of element damage caused by large current under the condition that the load is short-circuited is reduced.
In an embodiment of the invention, the processor 4 being configured to determine the state of the power supply loop 1 from the fluctuations of the voltage signal comprises: the processor 4 may be configured to:
determining the fluctuation rule of the voltage signal;
comparing the fluctuation rule with a preset fluctuation rule;
and under the condition that the fluctuation rule does not match the preset fluctuation rule, determining that the power supply loop 1 is short-circuited.
Specifically, in the case that the power supply loop 1 is not short-circuited, the voltage acquisition circuit 2 may acquire a fluctuating voltage signal during a period of time when the first controllable switch 2 is closed. Under the condition that the power supply loop 1 is short-circuited, the voltage signal acquired by the voltage acquisition circuit 2 tends to be stable after the first controllable switch 2 is closed, and no fluctuating voltage signal exists. Therefore, the processor 4 may determine the state of the power supply loop by comparing the fluctuation law of the voltage signal with a preset fluctuation law. In the embodiment of the present invention, when the fluctuation rule of the processor 4 does not match the preset fluctuation rule, for example, the voltage signal received by the processor 4 tends to be stable, it may be determined that the power supply loop 1 is short-circuited. The processor 4 further controls the power supply loop 1 to be disconnected, so as to avoid the situations that the current of the power supply loop 1 is large, the circuit board is burnt out and the circuit elements are damaged due to short circuit.
In an embodiment of the invention, the processor may be further configured to:
and under the condition that the fluctuation rule is matched with the preset fluctuation rule, determining that the power supply loop is not short-circuited.
Specifically, if the fluctuation rule of the processor 4 matches the preset fluctuation rule, for example, the voltage signal received by the processor 4 decreases from the high point to the low point in 1S, and the fluctuation process of decreasing from the high point to the low point matches the preset fluctuation rule, it may be determined that the power supply loop 1 is not short-circuited. In one example, in the case where the power supply circuit 1 is not short-circuited, the fluctuation rule of the voltage signal is that the power supply voltage at the moment when the power supply circuit 1 is turned on is slowly reduced to a preset voltage value within a set time t. If the instantaneous voltage signal of the power supply loop 1 is suddenly changed to a set value, the preset fluctuation rule is not matched. The processor 4 further controls the closing of the supply circuit 1. Thus, the load can be charged under the condition that the power supply loop 1 is not short-circuited, and the safety of the power supply loop 1 for charging the load is improved.
In an embodiment of the present invention, the configuration of the processor 4 to acquire the voltage signal acquired by the voltage acquisition circuit 2 may include:
the processor 4 is configured to acquire the voltage signal acquired by the voltage acquisition circuit 2 within a preset time.
Specifically, there is a dynamic process for the load capacitance equivalent to the load, and the voltage of the power supply loop 1 has a certain fluctuation law within a period of time when the first controllable switch 3 is closed. The processor 4 can judge whether the power supply circuit 1 is short-circuited by detecting the fluctuation rule of the voltage signal within the preset time of the closing of the first controllable switch 3. The preset time period may be a short period of time, such as 1s, 500ms, etc. The voltage signal obtained by the processor 4 may have fluctuations or may be a voltage signal that tends to be stable.
In an embodiment of the present invention, the preset fluctuation law is determined by the following formula:
U＝E(1-e-t/RC)；
wherein, U is a real-time voltage value of a load capacitor of the load, E is a steady-state voltage value of the load capacitor, C is a capacitance value of the load capacitor, and t is a preset time.
Specifically, after the power supply circuit 1 is turned on, because of the existence of the load capacitor, the voltage that can be charged by the load capacitor is the divided voltage after the resistor of the voltage acquisition circuit 2 and the load resistor are connected in series, and the charging time is determined by the R of the power supply circuit 1 and the voltage acquisition circuit and the load capacitor C. Therefore, the above formula is satisfied. There is now an RC parameter and where the load capacitance is known and constant. But R is adjustable, the charging time of the load capacitor can be adjusted by adjusting the resistance of the voltage acquisition circuit 2 until the load capacitor is charged to the steady-state voltage. Under the condition that the power supply loop 1 is short-circuited, the voltage of the power supply loop 1 is close to the power supply voltage and has no fluctuation process, and under the condition that the power supply loop 1 is not short-circuited, the fluctuation rule of the voltage of the power supply loop 1 accords with the fluctuation rule of the formula, so that whether the power supply loop 1 is short-circuited or not can be judged by comparing the fluctuation rule of the voltage signal with the formula, and the safety of the power supply loop 1 for charging a load is improved.
In addition, when the voltage of the voltage acquisition circuit 2 is detected to be 0V when the power supply loop 1 is turned on, it is determined that the power supply loop 1 is not connected to the load, and the processor 4 may not allow the power supply loop 1 to be turned on.
Through the description of the above principle, the design flow of the short circuit detection circuit corresponding to a specific load can be basically deduced: the load capacitance C is known from a design perspective; a proper voltage acquisition circuit 2 is provided to test the equivalent resistance of the load; detecting the voltage of the voltage acquisition circuit 2, and judging that the voltage reaches a steady state when the voltage is unchanged; the voltage division value of the equivalent resistance of the load is measured in a steady state, the resistance value of the resistance of the load is calculated according to the resistance of the voltage acquisition circuit 2, and the corresponding resistance of the voltage acquisition circuit 2 is calculated according to the formula, so that the capacitor is charged in a preset time, the charging process of the load can be accurately detected by the CPU in the period, and the characteristic of short-circuit detection of the power supply loop 1 is obviously distinguished.
Referring to fig. 2, fig. 2 is a schematic structural diagram of a load detection device according to another embodiment of the present invention. As shown in fig. 2, an embodiment of the present invention provides a load detection apparatus, the power supply circuit 1 may include a second controllable switch 11 for controlling on/off of the power supply circuit 1, and the processor 4 may be further configured to:
in case it is determined that the short circuit of the supply circuit 1 has not occurred, the second controllable switch 11 is controlled to close.
In particular, the second controllable switch 11 of the power supply circuit 1 may be arranged between the negative pole of the power supply and the negative pole of the power connector. When the second controllable switch 11 is closed, the power supply circuit 1 is turned on, the positive electrode of the power supply is electrically connected to the positive electrode of the load through the connector, the negative electrode of the power supply is electrically connected to the negative electrode of the load through the connector, and the power supply starts to charge the load. In the embodiment of the invention, under the condition that the power supply loop 1 is determined not to be short-circuited, the processor 4 controls the conduction of the power supply loop 1 again, so that the safety of the power supply loop 1 for charging the load is improved.
Referring to fig. 3, fig. 3 is a schematic diagram of a circuit structure of a load detection apparatus according to an embodiment of the present invention. As shown in fig. 3, in the embodiment of the present invention, the voltage acquisition circuit 2 may include a first resistor 21, a second resistor 22, and a third resistor 23; one end of the first resistor 21 is electrically connected with one end of the second resistor 22, and the other end of the first resistor 21 is electrically connected with the power supply loop 1 through the first controllable switch 3; the other end of the second resistor 22 is grounded, and a node between the first resistor 21 and the second resistor 22 is electrically connected to the processor 4 through a third resistor 23.
Examples of processor 4 may include, but are not limited to, a Central Processing Unit (CPU), a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) circuit, and so forth.
For example, in one example, the processor 4 may be a CPU, the first resistor 21 and the second resistor 22 may be used as voltage dividing resistors, and the third resistor 23 may be used as a current limiting resistor for ensuring that the LOAD voltage value of the CPU is lower than the tolerable voltage value.
In an embodiment of the present invention, the voltage acquisition circuit 2 further comprises a resistive component connected in parallel with the first resistor 21 and the second resistor 22 connected in series. The resistive component may comprise a plurality of resistors connected in series, and the resistive component may be used as a pre-charge resistor to provide a pre-charge current to the load, and may limit the voltage value at the pin of the processor 4. In one example, the voltage acquisition circuit 2 further includes a fourth resistor 24 and a fifth resistor 25 connected in series. One end of the fourth resistor 24 is electrically connected with one end of the fifth resistor 25, and the other end of the fourth resistor 24 is electrically connected with the power supply loop 1; the other end of the fifth resistor 25 is grounded.
Specifically, the fourth resistor 24 and the fifth resistor 25 are connected in series to form a resistor assembly, in parallel with the first resistor 21 and the second resistor 22 connected in series. The resistor component can be used as a pre-charging resistor, and the pre-charging resistor is connected in series with a charging loop in the pre-charging process to limit the magnitude of the pre-charging current. The power device is prevented from being damaged by large charging current generated by short circuit at the moment of power-on.
In the embodiment of the present invention, before the second controllable switch is closed 11, the CPU preferentially controls to close the first controllable switch 3, at this time, the current at the moment of conducting is determined by the resistance of the voltage acquisition circuit 2, and the resistance of the voltage acquisition circuit 2 is the resistance formed by connecting the divider resistor formed by the first resistor 21 and the second resistor 22 and the pre-charge resistor formed by the fourth resistor 24 and the fifth resistor 25 in parallel. The reason why the two resistors are connected in parallel here is that the first resistor 21 and the second resistor 22 are connected in series, and the CPU collects the voltage of the node of the first resistor 21 and the second resistor 22, and because the voltage of the node may be large, the first resistor 21 and the second resistor 22 are connected in series, so that the voltage of the pin of the CPU cannot exceed the maximum voltage that the pin can bear. The purpose of the series connection of the fourth resistor 24 and the fifth resistor 25 is to get rid of the limitation of the resistance of the first resistor 21 and the second resistor 22 and provide the main precharge current for the load.
In an embodiment of the invention, the processor 4 may be further configured to:
the charging time of the load is controlled by adjusting the resistance value of the resistance component.
Specifically, after the power supply circuit 1 is turned on, because of the existence of the load capacitor, the voltage that the load capacitor can charge at this time is the divided voltage after the resistor of the voltage acquisition circuit 2 and the load resistor are connected in series, and the charging time is determined by the resistor R and the load capacitor C outside the power supply circuit 1 and the load. In one example, the resistor R outside the load may be a resistance value after the first resistor 21, the second resistor 22 and the resistor assembly are connected in parallel. There is now an RC parameter and where the load capacitance is known and constant. But R is adjustable, the charging time of the load capacitor can be adjusted by adjusting the resistance of the voltage acquisition circuit 2 until the load capacitor is charged to the steady-state voltage. Under the condition that the power supply loop 1 is short-circuited, the voltage of the power supply loop 1 is close to the power supply voltage and has no fluctuation process, and under the condition that the power supply loop 1 is not short-circuited, the fluctuation rule of the voltage of the power supply loop 1 accords with or matches the fluctuation rule defined by the formula. Therefore, whether the power supply loop 1 is short-circuited can be judged according to whether the fluctuation rule of the voltage signal meets or matches the fluctuation rule defined by the formula, so that the safety of the power supply loop 1 for charging the load is improved.
In an embodiment of the present invention, the power supply loop 1 may further include a power source 12, a power connector 13, and a load connector 14; the positive electrode of the power source 12 is electrically connected with the positive electrode of the power connector 13, the negative electrode of the power source 12 is electrically connected with the negative electrode of the power connector 13, the positive electrode of the power connector 13 is electrically connected with the positive electrode of the load connector 14, the negative electrode of the power connector 13 is electrically connected with the negative electrode of the load connector 14, and the second controllable switch 11 is arranged between the negative electrode of the power source 12 and the negative electrode of the power connector 13.
In particular, the power supply circuit 1 is formed as a circuit by the second controllable switch 11, the power source 12, the power connector 13 and the load connector 14. The second controllable switch 11 is arranged between the negative pole of the power source 12 and the negative pole of the power connector 13, and when the second controllable switch 11 is turned off, the power supply circuit 1 is not turned on, and the load cannot be charged, and when the second controllable switch 11 is turned on, the power supply circuit 1 is turned on, and the load can be charged. Thus, the load can be charged again when the load detection device detects that the power supply loop 1 is not short-circuited and is connected with the load, and the risk of element damage caused by large current under the condition that the load is short-circuited is reduced. In addition, the circuit provided by the embodiment of the invention has great help for short circuit detection before starting up, is low in cost and wide in application range, and can be matched with an appropriate RC constant according to the characteristics of each load.
The circuit configuration of the load detection device shown in fig. 3 is taken as an example. In one embodiment, the circuit structure of the load detection apparatus of the present invention may include: the device comprises a power supply loop 1, a voltage acquisition circuit 2, a first controllable switch 3 and a processor 4. The first controllable switch 3 is arranged between the power supply circuit 1 and the voltage acquisition circuit 2, the power supply circuit 1 comprises a second controllable switch 11, and the processor 4 is electrically connected with the voltage acquisition circuit 2, the first controllable switch 3 and the second controllable switch 11.
The power supply loop 1 comprises a power supply 12, a power supply connector 13 and a load connector 14; the positive electrode of the power source 12 is electrically connected with the positive electrode of the power connector 13, the negative electrode of the power source 12 is electrically connected with the negative electrode of the power connector 13, the positive electrode of the power connector 13 is electrically connected with the positive electrode of the load connector 14, the negative electrode of the power connector 13 is electrically connected with the negative electrode of the load connector 14, and the second controllable switch 11 is arranged between the negative electrode of the power source 12 and the negative electrode of the power connector 13.
In particular, the power supply circuit 1 is formed as a circuit by the second controllable switch 11, the power source 12, the power source connector 13 and the load connector 14 and the load 15. The second controllable switch 11 is arranged between the negative pole of the power supply 12 and the negative pole BAT-of the power supply connector 13, the negative pole BAT-of the power supply connector 13 is connected with the negative pole PACK-of the load connector 14, the negative pole PACK-of the load connector 14 is connected with one end of the load 15, the other end of the load 15 is connected with the positive pole PACK + of the load connector 14, the positive pole PACK + of the load connector 14 is connected with the positive pole BAT + of the power supply connector 13, and the positive pole BAT + of the power supply connector 13 is connected with the positive pole of the power supply 12. When the second controllable switch 11 is open, the power supply circuit 1 is not conductive and the load 15 cannot be charged, and when the second controllable switch 11 is closed, the power supply circuit 1 is conductive and the load 15 can be charged. Thus, the load 15 can be charged again when the load detection device detects that the power supply circuit 1 is not short-circuited and the load 15 is connected, and the risk of component damage caused by large current when the load 15 is short-circuited is reduced. In addition, the circuit provided by the embodiment of the invention has great help for short circuit detection before starting up, is low in cost and wide in application range, and can be matched with an appropriate RC constant according to the characteristics of each load.
The voltage acquisition circuit 2 comprises a first resistor 21, a second resistor 22 and a third resistor 23; one end of the first resistor 21 is electrically connected with one end of the second resistor 22, and the other end of the first resistor 21 is electrically connected with the power supply loop 1 through the first controllable switch 3; the other end of the second resistor 22 is grounded, and a node between the first resistor 21 and the second resistor 22 is electrically connected to the processor 4 through a third resistor 23. In one example, the processor 4 may be a CPU, the first resistor 21 and the second resistor 22 may be voltage dividing resistors, and the third resistor 23 may be a current limiting resistor, which is used to ensure that the voltage value of the pin LOAD of the CPU is lower than the tolerable voltage value.
The voltage acquisition circuit further comprises a resistive component connected in parallel with the series connection of the first and second resistors 21, 22. In one example, the resistive component may include a fourth resistor 24 and a fifth resistor 25 connected in series. One end of the fourth resistor 24 is electrically connected with one end of the fifth resistor 25, and the other end of the fourth resistor 24 is electrically connected with the power supply loop 1; the other end of the fifth resistor 25 is grounded. The fourth resistor 24 and the fifth resistor 25 are connected in series to form a resistor assembly in parallel with the first resistor 21 and the second resistor 22 connected in series. The resistor component can be used as a pre-charging resistor, the pre-charging resistor is connected in series with a charging loop in the pre-charging process to limit the size of pre-charging current, and the phenomenon that a power device is damaged by large charging current generated by short circuit at the moment of electrifying is avoided.
In the embodiment of the present invention, before the second controllable switch is closed 11, the CPU preferentially controls to close the first controllable switch 3, at this time, the current at the moment of conducting is determined by the resistance of the voltage acquisition circuit 2, and the resistance of the voltage acquisition circuit 2 is the resistance formed by connecting the divider resistor formed by the first resistor 21 and the second resistor 22 and the pre-charge resistor formed by the fourth resistor 24 and the fifth resistor 25 in parallel. The reason why the two resistors are connected in parallel here is that the first resistor 21 and the second resistor 22 are connected in series, and the CPU collects the voltage of the node of the first resistor 21 and the second resistor 22, and because the voltage of the node may be large, the voltage of the CPU pin LOAD may not exceed the maximum voltage that the CPU pin LOAD can bear by using the first resistor 21 and the second resistor 22 connected in series. The purpose of the series connection of the fourth resistor 24 and the fifth resistor 25 is to get rid of the limitation of the resistance of the first resistor 21 and the second resistor 22 and provide the main precharge current for the load.
The processor 4 may control the closing of the first controllable switch 3 such that the power supply circuit 1 and the voltage acquisition circuit 2 form a path, thereby acquiring the voltage signal acquired by the voltage acquisition circuit 2 to determine the state of the power supply circuit 1 according to the fluctuation of the voltage signal. A dynamic process exists in the load capacitance equivalent to the load, and the voltage of the power supply loop 1 has a certain fluctuation rule in a period of time when the first controllable switch 3 is closed. Under the condition that there is not load or short circuit, even first controllable switch 3 is closed, the voltage signal that voltage acquisition circuit 2 gathered can not produce undulant law, and under the condition that does not have the short circuit, first controllable switch 3 is closed, and the voltage signal that voltage acquisition circuit 2 gathered can produce certain undulant law. Taking fig. 3 as an example, in the case that the power supply loop 1 is not short-circuited, the voltage value detected by the processor 4 will slowly decrease from the power voltage (BAT +) at the time of starting to turn on to the preset voltage value V for the preset time when the first controllable switch 3 is turned onPreset valueI.e. the voltage at point a1 (BAT +) -the real-time voltage value U of the load capacitor is the predetermined voltage value VPreset valueInstead of abruptly changing to V within a preset time of closure of the first controllable switch 3Preset value. The processor 4 (i.e., CPU) needs to continuously monitor the voltage at point B1 at the LOAD pin for a preset time t. According to the principle of serial resistance voltage division, the fluctuation rule of the point B1 can reflect the voltage fluctuation rule of the point A1 according to a certain proportion, and therefore whether the voltage value of the power supply loop 1 meets or matches the fluctuation rule is judged. In one example, the first controllable switch 3 is closed, i.e. the voltage signal fluctuates during a certain time when the power supply loop 1 and the voltage acquisition circuit 2 form a path, and the processor 4 compares the fluctuation law with the fluctuation lawSetting a fluctuation rule for comparison, and determining that the power supply loop 1 is short-circuited under the condition that the fluctuation rule does not match the preset fluctuation rule; and under the condition that the fluctuation rule is matched with the preset fluctuation rule, determining that the power supply loop 1 is not short-circuited. In another example, the first controllable switch 3 is closed, i.e. the voltage signal does not fluctuate during a certain time when the power supply loop 1 and the voltage acquisition circuit 2 form a path, and at this time, the processor 4 may determine that the power supply loop 1 is short-circuited. In case of a short circuit of the power supply circuit 1, the processor 4 may control the second controllable switch of the power supply circuit 1 to be turned off, and not to charge the load, so as to protect the components in the circuit.
According to the embodiment of the invention, the first controllable switch 3 is arranged between the power supply loop 1 and the voltage acquisition circuit 2, so that the processor 4 controls the first controllable switch 3 to be closed, the voltage signal acquired by the voltage acquisition circuit 2 is acquired, and the state of the power supply loop 1 is determined according to the fluctuation of the voltage signal. Therefore, the load detection device provided by the embodiment of the invention can not only detect whether a short circuit phenomenon exists, but also judge whether the load is connected, so that the risk of element damage caused by large current under the condition that the load is short-circuited is reduced.
It should be noted that the embodiments of the present invention are not limited to the above examples, and may be other circuit configurations capable of detecting a load short-circuit state and a connection state.
An embodiment of the present invention further provides an unmanned aerial vehicle charging system, which may include: unmanned device, power supply equipment and above-mentioned load detection device.
In embodiments of the present invention, the unmanned device may include, but is not limited to, a drone or an unmanned vehicle. The power supply equipment is electrically connected with the unmanned device and used for supplying power to the unmanned device. The load detection device is electrically connected with the unmanned device and used for detecting whether the unmanned device is short-circuited or not and whether the unmanned device is connected or not. In the load detection device of the embodiment, the first controllable switch is arranged between the power supply loop and the voltage acquisition circuit, the processor controls the first controllable switch to be closed, the voltage signal acquired by the voltage acquisition circuit within the preset time is acquired, and the state of the power supply loop is determined according to the fluctuation of the voltage signal. In one example, the fluctuation law of the voltage signal is compared with a preset fluctuation law. And under the condition that the fluctuation rule does not match the preset rule, determining that the power supply loop is short-circuited, and controlling the power supply loop to be disconnected by the processor to charge the unmanned device. And under the condition that the fluctuation rule is matched with the preset rule, determining that the power supply loop is not short-circuited, and controlling the power supply loop to be closed by the processor so as to charge the unmanned device. Therefore, the load detection device provided by the embodiment of the invention can not only detect whether a short circuit phenomenon exists, but also judge whether the load is connected, so that the risk of element damage caused by large current under the condition that the load is short-circuited is reduced.
Referring to fig. 4, fig. 4 is a schematic flow chart of a load detection method according to an embodiment of the present invention. As shown in fig. 4, an embodiment of the present invention further provides a load detection method, including the following steps:
step S41, controlling the first controllable switch to be closed so as to conduct the power supply loop and the voltage acquisition circuit;
step S42, acquiring a voltage signal acquired by a voltage acquisition circuit within a preset time;
and step S43, determining the state of the power supply loop according to the fluctuation of the voltage signal.
In the embodiment of the invention, the first controllable switch is arranged between the voltage acquisition circuit and the power supply loop, and the processor can control the first controllable switch to be closed so that the voltage acquisition circuit is conducted with the power supply loop, thereby acquiring the voltage signal acquired by the voltage acquisition circuit within the preset time and determining the state of the power supply loop according to the fluctuation of the voltage signal. The load capacitor equivalent to the load has a dynamic process, and the voltage of the power supply loop has a certain fluctuation rule within a period of time when the first controllable switch is closed. Under the condition of no load or short circuit, even if the first controllable switch is closed, the voltage cannot generate a fluctuation rule, and under the condition of no short circuit, the first controllable switch is closed, the voltage can generate a certain fluctuation rule.
In one example, the first controllable switch is closed, that is, the voltage signal fluctuates within a certain time when the power supply loop and the voltage acquisition circuit form a path, the processor compares the fluctuation rule with a preset fluctuation rule, and under the condition that the fluctuation rule does not match the preset fluctuation rule, the power supply loop is determined to be short-circuited; and under the condition that the fluctuation rule is matched with the preset fluctuation rule, determining that the power supply loop is not short-circuited. In another example, the first controllable switch is closed, that is, the voltage signal does not fluctuate for a certain time when the power supply loop and the voltage acquisition circuit form a path, and at this time, the processor may determine that the power supply loop is short-circuited. In case of a short circuit in the power supply circuit, the processor may control the second controllable switch of the power supply circuit to be turned off, without charging the load, so as to protect the components in the circuit. Therefore, the load detection device provided by the embodiment of the invention can not only detect whether a short circuit phenomenon exists, but also judge whether the load is connected, so that the risk of element damage caused by large current under the condition that the load is short-circuited is reduced.
In the embodiment of the present invention, the step S43 of determining the state of the power supply loop according to the fluctuation of the voltage signal includes:
determining a fluctuation rule of the voltage signal, and comparing the fluctuation rule with a preset fluctuation rule;
determining that the power supply loop is short-circuited under the condition that the fluctuation rule does not match the preset fluctuation rule;
and under the condition that the fluctuation rule is matched with the preset fluctuation rule, determining that the power supply loop is not short-circuited.
Specifically, when the power supply loop 1 is not short-circuited, the voltage acquisition circuit 2 may acquire a fluctuating voltage signal within a period of time when the first controllable switch 2 is closed. Under the condition that the power supply loop 1 is short-circuited, the voltage signal acquired by the voltage acquisition circuit 2 tends to be stable after the first controllable switch 2 is closed, and no fluctuating voltage signal exists. Therefore, the processor 4 may determine the state of the power supply loop by comparing the fluctuation law of the voltage signal with a preset fluctuation law. In the embodiment of the present invention, when the fluctuation rule of the processor 4 does not match the preset fluctuation rule, for example, the voltage signal received by the processor 4 tends to be stable, it may be determined that the power supply loop 1 is short-circuited. The processor 4 further controls the power supply loop 1 to be disconnected, so as to avoid the situations that the current of the power supply loop 1 is large, the circuit board is burnt out and the circuit elements are damaged due to short circuit.
In the embodiment of the present invention, when the fluctuation rule matches the preset fluctuation rule, for example, the voltage signal received by the processor 4 decreases from the high point to the low point in 1S, and the fluctuation process from the high point to the low point matches the preset fluctuation rule, it may be determined that the power supply loop 1 is not short-circuited. In one example, in the case where the power supply circuit 1 is not short-circuited, the fluctuation rule of the voltage signal is that the power supply voltage at the moment when the power supply circuit 1 is turned on is slowly reduced to a preset voltage value within a set time t. If the instantaneous voltage signal of the power supply loop 1 is suddenly changed to a set value, the preset fluctuation rule is not matched. The processor 4 further controls the closing of the supply circuit 1. Thus, the load can be charged under the condition that the power supply loop 1 is not short-circuited, and the safety of the power supply loop 1 for charging the load is improved.
Further, in an embodiment of the present invention, the load detection method further includes:
under the condition that the power supply loop is determined not to be short-circuited, controlling a second controllable switch arranged on the power supply loop to be closed
In particular, the second controllable switch 11 of the power supply circuit 1 may be arranged between the negative pole of the power supply and the negative pole of the power connector. When the second controllable switch 11 is closed, the power supply circuit 1 is turned on, the positive electrode of the power supply is electrically connected to the positive electrode of the load through the connector, the negative electrode of the power supply is electrically connected to the negative electrode of the load through the connector, and the power supply starts to charge the load. In the embodiment of the invention, under the condition that the power supply loop 1 is determined not to be short-circuited, the processor 4 controls the conduction of the power supply loop 1 again, so that the safety of the power supply loop 1 for charging the load is improved.
It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in the process, method, article, or apparatus that comprises the element.
The above are merely examples of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.
Claims (13)
1. A load detection device, comprising:
a power supply loop for supplying power to a load;
a voltage acquisition circuit configured to acquire a voltage signal from the power supply loop;
the first controllable switch is arranged between the voltage acquisition circuit and the power supply loop; and
a processor configured to:
controlling the first controllable switch to close;
acquiring a voltage signal acquired by the voltage acquisition circuit;
and determining the state of the power supply loop according to the fluctuation of the voltage signal.
2. The load detection device of claim 1, wherein the processor being configured to determine the state of the power supply loop from fluctuations in the voltage signal comprises: the processor is configured to:
determining the fluctuation rule of the voltage signal;
comparing the fluctuation rule with a preset fluctuation rule;
determining that the power supply loop is short-circuited under the condition that the fluctuation rule does not match the preset fluctuation rule;
and under the condition that the fluctuation rule is matched with the preset fluctuation rule, determining that the power supply loop is not short-circuited.
3. The load detection device of claim 2, wherein the power supply loop comprises a second controllable switch for controlling the switching of the power supply loop, the processor further configured to:
and controlling the second controllable switch to be closed under the condition that the power supply loop is determined not to be short-circuited.
4. The load detection device of claim 1, wherein the processor configured to obtain the voltage signal collected by the voltage collection circuit comprises:
the processor is configured to acquire a voltage signal acquired by the voltage acquisition circuit within a preset time.
5. The load detection device according to claim 4, wherein the preset fluctuation law is determined by the following formula:
U＝E(1-e-t/RC)；
the method comprises the steps of obtaining a real-time voltage value of a load capacitor of a load, obtaining a steady-state voltage value of the load capacitor, obtaining a capacitance value of the load capacitor, and obtaining a preset time t.
6. The load detection device of claim 1, wherein the voltage acquisition circuit comprises a first resistor, a second resistor, and a third resistor; one end of the first resistor is electrically connected with one end of the second resistor, and the other end of the first resistor is electrically connected with the power supply loop through the first controllable switch; the other end of the second resistor is grounded, and a node between the first resistor and the second resistor is electrically connected with the processor through the third resistor.
7. The load detection device according to claim 6, wherein the voltage acquisition circuit further comprises a resistor component connected in parallel with the first resistor and the second resistor connected in series; the resistance component comprises a fourth resistance and a fifth resistance which are connected in series.
8. The load detection device of claim 7, wherein the processor is further configured to:
and controlling the charging time of the load by adjusting the resistance value of the resistance component.
9. The load detection device of claim 3, wherein the power supply circuit further comprises a power source, a power connector, and a load connector; the positive pole of the power supply is electrically connected with the positive pole of the power supply connector, the negative pole of the power supply is electrically connected with the negative pole of the power supply connector, the positive pole of the power supply connector is electrically connected with the positive pole of the load connector, the negative pole of the power supply connector is electrically connected with the negative pole of the load connector, and the second controllable switch is arranged between the negative pole of the power supply and the negative pole of the power supply connector.
10. An unmanned device charging system, comprising: an unmanned device, a power supply apparatus, and the load detection device of any one of claims 1 to 9.
11. A method of load detection, comprising:
controlling the first controllable switch to be closed so as to conduct the power supply loop and the voltage acquisition circuit;
acquiring a voltage signal acquired by the voltage acquisition circuit within a preset time;
and determining the state of the power supply loop according to the fluctuation of the voltage signal.
12. The load detection method of claim 11, wherein determining the state of the power supply loop based on the fluctuation of the voltage signal comprises:
determining a fluctuation rule of the voltage signal, and comparing the fluctuation rule with a preset fluctuation rule;
determining that the power supply loop is short-circuited under the condition that the fluctuation rule does not match the preset fluctuation rule;
and under the condition that the fluctuation rule is matched with the preset fluctuation rule, determining that the power supply loop is not short-circuited.
13. The load detection method of claim 12, further comprising:
and under the condition that the power supply loop is determined not to be short-circuited, controlling a second controllable switch arranged on the power supply loop to be closed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202011474753.8A CN112578227A (en) | 2020-12-14 | 2020-12-14 | Load detection device and method, and unmanned device charging system |
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| CN202011474753.8A CN112578227A (en) | 2020-12-14 | 2020-12-14 | Load detection device and method, and unmanned device charging system |
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| CN112578227A true CN112578227A (en) | 2021-03-30 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114624633A (en) * | 2022-05-17 | 2022-06-14 | 陕西天视致远航空技术有限公司 | HDMI (high-definition multimedia interface) port plugging detection system and method, electronic equipment and storage medium |
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2020
- 2020-12-14 CN CN202011474753.8A patent/CN112578227A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114624633A (en) * | 2022-05-17 | 2022-06-14 | 陕西天视致远航空技术有限公司 | HDMI (high-definition multimedia interface) port plugging detection system and method, electronic equipment and storage medium |
| CN114624633B (en) * | 2022-05-17 | 2022-09-30 | 陕西天视致远航空技术有限公司 | HDMI (high-definition multimedia interface) port plugging detection system and method, electronic equipment and storage medium |
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Address after: 510000 Block C, 115 Gaopu Road, Tianhe District, Guangzhou City, Guangdong Province Applicant after: Guangzhou Jifei Technology Co.,Ltd. Address before: 510000 Block C, 115 Gaopu Road, Tianhe District, Guangzhou City, Guangdong Province Applicant before: Guangzhou Xaircraft Technology Co.,Ltd. |